Fat-Loss Peptides Beyond GLP-1s: The Metabolic Compounds Ranked

Fat loss peptides are research compounds studied for the "energy out" side of metabolism: how well cells burn fat. GLP-1s work on the other side, "energy in", by turning down appetite. The non-GLP-1 group in this guide is 5-Amino-1MQ, SLU-PP-332, L-carnitine, MOTS-c and Tesamorelin. Most of them are not stimulants. They work in targeted ways that have been studied mainly in cells and animals.

Everyone is talking about GLP-1s, and for good reason. In clinical trials, nothing else comes close for total weight loss. But GLP-1s do one specific job: they target appetite. A whole other group of compounds is studied on the opposite side, which is how much fat the body actually burns. Many people lump these in with old-style "fat burners". In fact they are a very different, and far more interesting, class than the old stimulants. This guide covers what the non-GLP-1 metabolic peptides do in research and which ones are worth your time. It also explains why even the best of them boost your effort rather than replace it.

How does fat loss actually work?

Fat loss comes down to energy balance. Your body runs on energy, measured in calories. Take in more than you burn, and the extra is stored as fat. Burn more than you take in, and your body draws on its fat stores to cover the gap. That is the whole thing: energy in versus energy out.

This is basic physics, and it applies to every living animal. No peptide, drug or superfood gets around it. So the only way any compound can help is by nudging one side of the balance. Appetite drugs like the GLP-1s work on "energy in". Everything in this article is studied on the other side, energy out.

The compounds here work on energy out in two ways.

• Drivers. In animal studies, SLU-PP-332 and 5-Amino-1MQ raised energy expenditure (calories burned at rest) and fat oxidation (burning fat for fuel). The animals lost fat without eating any less. That is the same way exercise tips the balance, so these compounds do real work.
• Helpers. L-carnitine is the machinery that moves fat into the cell's furnace, rather than a driver. Research suggests it needs demand, such as training or eating less, before it makes a difference.

That is why people build any stack on a solid base of diet and training. The mechanism is real, but it works best on top of the basics.

Which non-GLP-1 metabolic peptides are worth knowing?

The core three are 5-Amino-1MQ, SLU-PP-332 and L-carnitine. MOTS-c and Tesamorelin sit in the same area. Each one is studied for a different way of burning fat. Here is what the research says about each.

What is 5-Amino-1MQ and how does it work?

5-Amino-1MQ is a small molecule that blocks an enzyme called NNMT. NNMT sits in fat cells and uses up two things. One is NAD+, a helper molecule cells need to turn food into energy. The other is methyl groups, small chemical tags cells use to switch processes on and off.

Block NNMT, and more NAD+ is left inside the fat cell. Research links this to three effects:

• It switches on SIRT1, a cell "housekeeping" enzyme that runs on NAD+.
• It nudges white fat toward beige fat, a more active type of fat that burns energy instead of just storing it.
• It raises the energy that fat cells (adipocytes) burn.

The headline from the animal work is striking: mice lost fat without eating less (Neelakantan 2018; see also the related NNMT work in Kraus 2014, Nature). It is not a stimulant, and it works when taken by mouth in research. Doses in the literature are around 100 to 200 mg a day. It is a promising research compound that has been well tolerated so far. In research it is also the one that pairs most naturally with a GLP-1.

What is SLU-PP-332, the "exercise mimetic"?

SLU-PP-332 is a research compound called an "exercise mimetic", meaning it copies some effects of exercise. It switches on the same pathways that endurance training does.

It works on the ERR family of receptors. These are proteins inside the cell that switch genes on. They team up with PGC-1-alpha, the master switch that tells a cell to build more energy machinery. In animal studies, the result looked like the changes cardio produces (Billon 2023):

• Cells built more mitochondria, the tiny power plants inside every cell.
• More fat was burned for fuel.
• Muscle shifted toward the tireless, endurance type that cardio builds.

Like 5-Amino-1MQ, it is not a stimulant and is taken by mouth. It has a short half-life (how long it stays active before the body clears it), so research doses are taken more often. It is the newest compound in this group, and the science is exciting. It is also on the anti-doping radar, so it is not for tested athletes.

What does L-carnitine do for fat metabolism?

L-carnitine is the proven workhorse of the group. It is the only one here with an approved medicine version (Carnitor, used for true carnitine deficiency). Its mechanism is also the best understood.

Its job is simple. It is the shuttle that carries long-chain fats into the mitochondria so they can be burned (Wall 2011). No carnitine, no fat into the furnace.

In research it is used in two ways:

• By mouth, usually as L-carnitine-L-tartrate, a few grams a day. It is often taken with carbs, because insulin helps drive it into muscle.
• As an injection, either subcutaneous (just under the skin) or intramuscular (into the muscle).

Intravenous infusions (directly into a vein) are used in clinics, but we do not recommend the IV route. Large IV infusions are also restricted under anti-doping rules.

What about MOTS-c and Tesamorelin?

MOTS-c and Tesamorelin belong in the same area, and each has its own deep-dive.

MOTS-c is a mitochondrial-derived peptide, a signal molecule made by the mitochondria themselves. It is studied for signals inside the cell that look like the effects of training. It has a "paradox" worth understanding before you run it: research suggests it works best once the groundwork is in place. Full detail is in the MOTS-c deep-dive.

Tesamorelin is the one studied for visceral fat, the deep belly fat packed around the organs. It works through the growth-hormone axis, the body's own system for releasing growth hormone and responding to it. So it does not burn fat directly. It is covered with the GH peptides.

What are the limits of the fat-loss peptide research?

These compounds have real mechanisms behind them. It also helps to know where the research stands today.

• Most of the data is preclinical. That means it comes from lab and animal studies, not yet from people. Human data on 5-Amino-1MQ is still thin, and on SLU-PP-332 it barely exists yet.
• The effect in animals is far smaller than a GLP-1's. These compounds tilt the energy balance. They do not match the appetite drugs for total weight loss.
• Diet still matters most. These compounds add to your effort; they do not replace it. L-carnitine in particular needs demand, such as training, for its mechanism to matter.
• L-carnitine is hard to load by mouth. Getting it into muscle is the slow step, which is why people time it with carbs.
• There is a long-running debate about TMAO. TMAO is a by-product gut bacteria make when they digest carnitine. Some studies link it to heart and blood vessel risk (Koeth 2013).

So think of these compounds as a multiplier on a real base of training and diet, not a substitute for it.

Metabolic peptides vs clen, T3 and DNP: how do they compare?

The metabolic peptides chase the same goal as clenbuterol, T3 and DNP, which is burning more fat. The difference is how. They use targeted, non-stimulant mechanisms instead of forcing the whole body. They give up some peak strength in exchange for a much cleaner risk profile.

For decades, "fat burner" meant one of three things, and all three came at a price.

• Clenbuterol is a stimulant. It is a beta-2 agonist, meaning it switches on the same receptors adrenaline does. It raises your metabolic rate by revving up your nervous system. It works, but it also brings tremors, cramps, a racing heart and poor sleep. With long-term use it puts real strain on the heart. You feel wired and on edge.
• T3 (liothyronine) is thyroid hormone taken from outside, rather than made by your own gland. It burns fat well, but it also burns muscle. It shuts down your own thyroid, which makes coming off it hard. And it pushes your whole system into overdrive.
• DNP (2,4-dinitrophenol) is the extreme. It makes your cells waste energy as heat. That is very effective, and it can kill. People die of overheating on it every year, and there is almost no margin for error. It is the clearest example of brute force with a body count.

Notice what those three have in common: none of them is a peptide. Clenbuterol is a stimulant drug, T3 is a thyroid hormone, and DNP is an industrial chemical. The old way to burn fat meant blunt drugs and chemicals that hit the whole body. You simply accepted the damage. The metabolic peptides are a different and more targeted kind of tool.

They chase the same goal: more fat burned and a higher metabolic ceiling. But they get there through targeted, non-stimulant mechanisms:

• saving NAD+ in fat cells (5-Amino-1MQ)
• copying the effects of exercise (SLU-PP-332)
• helping the fat shuttle (L-carnitine)
• signalling better mitochondrial efficiency (MOTS-c)

They will not match DNP for raw force, and we would not want them to. What they offer is the same direction without the racing heart, the muscle loss or the real danger. That is the bigger story of peptides as a category. They are a smarter, more precise version of tools that used to cause serious harm. Smarter, not harder, and a great deal safer.

Can you stack metabolic peptides with a GLP-1?

Yes, in research these pair well with a GLP-1. A GLP-1 works on the intake side. These compounds are studied on the burn side, so the two do not overlap.

A GLP-1 such as retatrutide or tirzepatide targets appetite and helps you eat less (see the GLP-1 comparison). A metabolic peptide like 5-Amino-1MQ or SLU-PP-332 is studied for fat burning and metabolic rate alongside it. Because they do different jobs, the benefits can add up instead of just piling on side effects. What makes no sense is stacking two appetite suppressants. It also makes no sense to expect a metabolic compound to do a GLP-1's job.

Why doesn't Primogen stock AOD-9604?

AOD-9604 is a fragment of growth hormone. It was designed to keep the fat-burning part of growth hormone without the growth effects. It is one of the most marketed fat-loss peptides online. We do not stock it, because it failed its main human obesity trial.

In rodents, it looked excellent. In humans, it did not deliver. Its main trial was a 24-week Phase 2b study, a mid-stage trial that tests whether a drug actually works. It had around 500 people and ran alongside diet and exercise. AOD-9604 failed to beat placebo, and the company stopped obesity development back in 2007.

Its best human result came from a smaller, earlier study that was never peer-reviewed. That result was about 2 kg more than placebo. For comparison, GLP-1s report 15 to 25% body-weight loss in their trials.

There is more to know:

• It is banned by WADA, the World Anti-Doping Agency, which sets the banned list for sport.
• The US compounding advisory committee voted against allowing it in late 2024.
• Sellers like to cite its "GRAS safe" badge. GRAS stands for Generally Recognized As Safe, and a company can simply declare it about its own product. It is not an FDA review of either safety or weight loss.

Its safety record is clean. But a clean safety record on a compound that did not work in trials is not a reason to sell it.

So we do not stock AOD-9604. If a well-designed human trial ever shows it works, we will look at it again. Until then, we would rather tell you the famous name does not hold up than take your money for it.

Referenced products

5-Amino-1MQ

Rp 1.890.000 · 50mg

SLU-PP-332

Rp 3.490.000 · 30mg

L-Carnitine

Rp 990.000 · 10ml · 600mg/ml

MOTS-c

Rp 2.390.000 · 40mg

Tesamorelin

Rp 1.790.000 · 10mg

Which fat loss peptide should you research?

It depends on what you want to study. 5-Amino-1MQ suits a non-stimulant compound studied alongside a GLP-1. SLU-PP-332 is the exercise-mimetic option. L-carnitine is the proven fat shuttle with the most evidence. Here it is mapped out:

• Want a non-stimulant that saves NAD+, alongside a GLP-1? 5-Amino-1MQ is the cleanest non-stimulant pairing in the research.
• Drawn to the exercise angle (mitochondria, endurance, fat burning)? SLU-PP-332 is the most interesting. It is early, and it is on the doping list.
• Want the proven workhorse? L-carnitine, used properly: the right form, taken with carbs, alongside training.
• Interested in the mitochondrial signal route? Read the MOTS-c deep-dive first, including the paradox.
• Researching visceral fat in particular? That is Tesamorelin's lane, covered with the GH peptides.

Whichever you research, keep your expectations realistic. The mechanism tilts the energy balance in animal studies, and the effect in people is still being proven. A solid base of training and diet does the heavy lifting.